Apparatus for producing a core spun yarn

ABSTRACT

The production of a core spun yarn ( 46 ) by means of fluid technique is performed with an apparatus according to the invention. The apparatus substantially comprises a fiber guide conduit ( 13 ) with a fiber guide surface ( 28 ) for guiding the fibers (F) of the fiber structure and a guide apparatus for guiding the continuous thread (C) into an inlet orifice ( 35 ) of a yarn guide conduit ( 7, 45 ) and a fluid device for producing a swirl flow about the inlet orifice ( 35 ) of the yarn guide conduit ( 7, 45 ). It further comprises with respect to the fiber guide surface ( 28 ) a guide means ( 5 ) contained in the thread guide means ( 4 ) for at least one continuous thread (C), so that said at least one continuous thread (C) can be spun over by the fibers (F) on the spindle ( 6, 32 ). The guide means ( 5 ) is either a groove ( 5.1 ) which is associated with the fiber guide surface ( 28 ), a bore ( 5.2 ) disposed below the fiber guide surface ( 28 ) or an individual tube-like element ( 5 c), or one that is combined with a groove ( 5.1 ) or a bore ( 5.2 ), which is introduced in a thread guide means ( 4 ), with the axis of groove ( 5.1 ), bore ( 5.2 ) and tube-like element ( 5 c) being in true alignment with the axis of the yarn guide conduit ( 7, 45 ).

[0001] The invention relates to an apparatus and a method for producing a spun yarn from a fibre structure which spins over at least one separately supplied continuous thread into a core spun yam, comprising a fibre guide conduit with a fibre guide surface for guiding the fibres of the fibre structure and a guide apparatus for guiding the continuous thread into an inlet orifice of a yarn guide duct, and further comprising a fluid device for producing an eddy current around the inlet orifice of the yarn guide conduit. An apparatus for producing a core spun yarn is known from DE 198 04 341. It concerns a ring spinning apparatus with which at least one continuous thread can be supplied to the drafted sliver and is spun together into a yarn. It is not known, however, to produce a core spun yarn by fluid guidance. An apparatus for producing a yarn from staple fibre by means of fluid guidance is therefore the object of the present invention

[0002] An apparatus in which the fibres are guided for the incorporation of the front fibre ends by the rear part of the fibres in a fibre guide and by means of which the fibres can be grasped in this way by the produced air vortex in order to produce an even and strong yarn is described in U.S. Pat. No. 5,528,895. In order to guide the fibres a pin is provided which is disposed centrically with respect to the yarn guide conduit and about which the supplied fibres extend spirally in the direction towards the yarn guide conduit in order to be spun. This central device prevents the contribution of a continuous thread, or several thereof, which forcebly need to pass through the center of the yarn guide conduit.

[0003] The object is substantially achieved in such a way that a fibre guide surface faces a spindle with a yarn guide conduit, through and by which the fibres are guided in a substantially flat formation in a mutually adjacent way towards the inlet orifice of the yarn guide conduit and the fibre guide element is additionally provided with the fibre guide surface witih a guide means incorporated in the thread guide means for the at least one continuous thread, so that the same can be spun over by the fibres on the spindle.

[0004] Further details on the solution and advantageous embodiments are described in the description with the figures.

[0005] The invention is now explained in closer detail by reference to the drawing merely illustrating possible embodiments, wherein:

[0006]FIGS. 1a-1 c show in sections and in a schematic way the most essential parts of an apparatus for “open-end” core spun yarn production with the supply of a continuous thread. The supply of the fibres is not shown here. It will be discussed in connection with FIGS. 2, 2a-c.

[0007]FIGS. 2, 2.1 show the invention according to FIGS. 1a and 1 b substantially accoring to the lines of intersection I-I (FIG. 2b) and the lines of intersection I′-I′ in FIG. 2b.1, with a middle element being shown in a non-sectional manner.

[0008]FIGS. 2a, 2 a.1 show a sectional view according to the lines of intersection II-II of FIG. 2 and II′-II′ of FIG. 2.1.

[0009]FIGS. 2b, 2 b.1 show a cross-sectional view according to the lines of intersection III-III of FIG. 2 and III′-III′ of FIG. 2.1.

[0010]FIG. 2c shows a sectional view of FIG. 2, shown enlarged.

[0011]FIGS. 3a, 3 b show proposals for apparatuses for inserting the continuous fibre in connection with FIGS. 2 and 2b in a schematic representation.

[0012]FIG. 1a-c shows a housing 1 with the housing parts 1 a and 1 b with a nozzle block 2 which is built into the same and comprises jet nozzles 3 by means of which the said turbulent flow is produced as well as the said fibre and thread guide means 4, which is drawn in this case with a conveying surface for conveying the fibres F, with a guide means 5 incorporated in the same for a continuous thread C which can be drawn off from a bobbin S via a deflection roller 9, which thread can be a continuous filament, a staple fibre yam, a mono- or multi-filament for a producing a core spun yarn.

[0013] The jet nozzles 3 produce the turbulent flow for the swirl by which the fibres F supplied via the fibre guide means 4 are twisted in a sense of rotation about the face side 6 a of the so-called spindle 6 and are guided into a yarn guide conduit 7 of the spindle 6. The fibres F are conveyed in a fibre guide conduit 13 on the said conveying surface of the fibre and thread guide means 4 as a result of sucked-in air against the face side 6 a of the spindle 6. The sucked air is produced as a result of an injector effect of jet nozzles 3 which are provided in such a way that on the one hand the aforementioned air swirl is produced, but on the other hand air is also sucked through the fibre guide conduit 13. Said air escapes along a conical part 6 b of the spindle 6 through a ventilation space 8 into an air outlet 10. The compressed air for the jet nozzles 3 is supplied evenly to the jet nozzles by means of a compressed air distribution chamber 11.

[0014] It is discussed further below how the continuous thread C can be placed in the apparatus. The guide means 5 for the continuous thread C is aligned in such a way that it is introduced centrically or that the guided continuous thread C is introduced centrically in the inlet orifice 6 c of the spindle 6.

[0015] The fibre and thread guide means 4 is preferably designed in such a way that the fibre guide surface 28 comes to lie horizontally, as is shown in FIG. 1a, or that instead the fibre and thread guide means 4 is shaped in a tapering manner towards the face side 6 a of the spindle as shown in FIG. 1b, e.g. at all or only some sides. This leads to the advantage that the fibres F reach the inlet orifice 6 c already in a very central way to the face side 6 a facing the inlet orifice 6 c. The guide means 5 incorporated in the fibre and thread guide means 4 can be in both cases a groove for receiving a continuous thread C or a continuous bore through the fibre and thread guide means 4, through which the continuous thread C is guided. Instead of strongly shaping the fibre and thread guide means 4 in a strongly tapering way, it is also possible to provide as a further possibility a tube-like element 5 c, e.g. a small tube provided with a continuous opening, in the fibre and thread guide means 4 (FIG. 1c) which is preferably situated closer to the inlet orifice 6 c and by means of which the continuous thread C is guided in a centrical way to the inlet orifice C. If the tube-like element 5 c is only a part of the guide means 5, the reamining guide means 5 in the thread guide means 4 can be arranged as a groove or bore. If the fibre and thread guide means 4 is provided with an arrangement tapering towards the face side 6 a of the spindle 6 or with a tube-like element 5 c, the fibres F are very centrically aligned towards the yarn guide conduit 7 already at the end of the fibre and thread guide means 4 or the tube-like element 5 c.

[0016]FIGS. 2, 2a and 2 c show a fibre delivery edge 29 which is situated very close to an inlet orifice 35 of a yarn guide conduit 45 which is disposed within a so-called spindle 32 Advantageously, the fibre delivery edge 29 is disposed with a predetermined distance A between the same and the inlet orifice 35 as well as a predetermined distance B between an imaginary plane E and said central line 47, which plane contains the edge and is parallel to a central line 47 of the yarn guide conduit 45.

[0017] The distance A corresponds depending on type of fibre and mean fibre length and the respective experimental results to a range of 0.1 to 1.0 mm. The distance B depends on a diameter G of the inlet orifice 35 and lies, depending on the results of the trials, within a range of 10 to 30% of the said diameter G.

[0018] Furthermore, the fibre delivery edge 29 is provided with a length D.1 (FIG. 2a) which is at a ratio of 1:5 to the diameter G of the yarn guide conduit 45 and is formed by a face side 30 of a fibre conveying element 27 (according to FIG. 1a-c of the fibre and thread guide means 4) and a fibre guide surface 28 of the element 27. The face side 30, with its height O, is situated within the range of diameter G and is provided with an empirically determined distance H between the plane E and the opposite inner wall 48 of the yarn guide conduit 45. If the fibre and thread guide means 4 is arranged, as in FIG. 1b, tapering towards the face side 6 a of the spindle 6 or as in FIG. 1c with a tube-like element 5 c, all distances also need to be determined empirically in a respective way.

[0019] The fibre conveying element 27 is further provided with a guide means 5.1 (one groove FIG. 2b) or 5.2 (a bore, FIG. 2b.1) for guiding the continuous thread C and is guided in a supporting element 37 received in the nozzle block 20 and forms with this supporting element a free space forming the fibre guide conduit 27 and is provided at the entrance with a fibre receiving edge 31 about which the fibres are guided which are supplied by a fibre conveying roller 39. These fibres are lifted off from the fibre conveying roller 39 by means of a suction air flow from the conveying roller and conveyed through the fibre guide conduit 26. The suction air flow is produced by an air flow produced in jet nozzles 21 with a blowing direction 38 as a result of an injector effect.

[0020] Said nozzle jets are, as shown in FIGS. 2 and 2b, positioned in an inclined manner in a nozzle block 20 with an angle β on the one hand in order to produce the said injector effect and with an angle α on the other hand in order to produce an air swirl which rotates with a direction of rotation 24 along a cone 36 of the fibre conveying element 27 and about the front surfaces 34 of the spindle in order to form, as will be explained below, a yarn in the yarn guide conduit 45 of the spindle 32. The fibre guide surface 28 is provided in the direction of fibre guidance with a recess 5.1 for guiding the continuous thread C (FIG. 2a from above, FIG. 2b in a sectional view). The endless thread C is placed in said recess 5.1 and thereafter spun over by the fibres F.

[0021] The air flow produced by nozzles 21 in a swirl chamber 22 escapes to the atmosphere along a spindle cone 33 through a ventilation conduit 23 formed about a so-called spindle 32 (no. 6 in FIG. 1a-c) or to a suction device. In order to form a core spun yarn 46, the fibres supplied by the fibre conveying roller 39 are lifted off from the fibre conveying roller 39 by means of the said suction air stream in the fibre guide conduit 26 as has already been mentioned and are guided on the fibre guide surface 28 in a conveying direction 25 together with the continuous thread C towards the fibre delivery edge 29. From said delivery edge, the ends of the fibres are guided through the spindle inlet orifice 35 into the yarn guide conduit 45, whereas the other second ends 49 of said fibres flip over once said second ends are free and are grasped by the rotating air flow. During the further conveyance of the fibres in the yam guide conduit 45 about the endless thread C, a core spun yarn 46 is thus produced which has a yarn character similar to the ring yarn.

[0022] This process is also shown similarly in the FIGS. 2.1 through 2 b.1. It is shown that the fibres F supplied with the fibre conveying roller 39 are guided together with the continuous thread C (FIG. 2.1 from the side; FIG. 2b.1 in a sectional view) guided through a bore 5.2 in the fibre conveying element 27 in the conveying direction 25 on the fibre guide surface 28 towards the fibre delivery edge 29, namely—as is shown in FIG. 2a.1 by means of a converging fibre flow which is continually constricted towards the inlet orifice 35. This constriction is made for the reason that the ends which are at the front as seen in the running direction of the fibres and are already incorporated in the twisted yarn 46 have the tendency to migrate in the direction towards the constriction, so that the further backwardly disposed second ends of the fibres are also displaced in the direction towards the constriction. This only occurs until the second ends 49 of the fibres F are grasped by the said air swirl in order to be turned about the front surface 34 of the spindle and are pulled with the thread draw-off speed into the inlet orifice 35 and are provided with the twist required for the yarn formation.

[0023] In FIG. 2a.1, the width d.1 is shown enlarged by means of dot-dash lines. This is to show on the one hand that this width can be enlarged and to illustrate on the other hand that the enlarged width d.1 reduces the swirl chamber 22 as shown in FIG. 2a under certain circumstances, or may even disturbingly change the same, in that the swirl flow can no longer develop in the same in such a way that the fibre ends 49 can be grasped with the desired energy by the swirl flow. This needs to be determined with empirical trials.

[0024] The aforementioned yarn formation occurs after the beginning of a piecing process of any kind, e.g. in which a yarn end of an already existing yarn is guided back through the yarn guide conduit 45 to the zone of the spindle inlet orifice 35 to such an extent that fibres of said yarn and are opened by the already rotating air flow to such a wide extent that ends of fibres newly supplied through the fibre guide conduit 26 can be grasped by this rotating fibre structure. By a renewed draw-off of the introduced yarn end, the following parts of the newly supplied fibres which are already able to wind around the ends disposed in the orifice part of the yarn guide conduit, are entrained, so that subsequently the said yarn can be newly spun with a substantially predetermined piecing. At the beginning of the piecing process it is possible with the proposed apparatus to shoot in the continuous thread C from one end of the spinning apparatus through the thread and fibre guide means 4 and through the yarn guide conduit 46, so that it is grasped at the other end and can be attached to a wound lap for example. Proposals for apparatuses are described further below by reference to schematic representations with which the shooting and the insertion process can be simplified substantially.

[0025] The fibre guide surface 28 or the fibre delivery edge 29 can be shaped differently, e.g. concavely, convexly or waved. These shapes are used for the different fibre guidance on the fibre guide surface 28 and must be determined empirically depending on the type of fibre and the fibre length. It has been noticed that concave is suitable for so-called “slippery” fibres and convex for so-called “adhesive” fibres. “Slippery” fibres are understood as being such which have a low mutual adhesion and “adhesive” fibres are such which have a stronger mutual adhesion.

[0026]FIGS. 3a and 3 b show a proposal for a solution for modifying the above apparatus (figs. concerning 2 ff.) for the insertion of the continuous thread C prior to piecing The figs. show a nozzle block 20 according to the FIGS. 2 and 2.1. In FIG. 3a, a part 20′ of the nozzle block 20 including the supporting element 37 can be flipped open along line M according to FIG. 2b and can be lifted off in such a way that the fibre guide surface 28 and the groove 5.1 which is introduced therein are freely accessible. A continuous thread C for producing a core spun yarn can be inserted with ease without having to thread the same through groove 5.1. In the case of guide means 5 in form of a bore 5.2, a part of the fibre guide elements 27′, as is schematically shown in FIG. 3b, is flipped downwardly along line M′ according to FIG. 2b.1. Bore 5.2 is thus uncovered and continuous thread C can be inserted. In the case of a tube-like element 5 c which is inserted into the thread guide means 4 and is shorter than the thread guide means 4, an upper or lower part of the nozzle block 20 is flipped away according to the groove 5.1 or bore 5.2 remaining on the length of the thread guide means 4. As a result of the tube-like element 5 c it is necessary to thread or shoot in a continuous thread C according to conventional technique; the path is reduced by a short tube-like element which is shorter than the thread guide means 4 and in the two other cases the shooting-in process can be omitted completely. 

1. An apparatus for producing a spun yarn from a fibre structure which spins over at least one separately supplied continuous thread (C) into a core spun yarn (46), characterized by a thread guide means (4) with a fibre guide conduit (13, 26) with a fibre guide surface (28) for guiding fibres (F) of the fibre structure into an inlet orifice (6 c, 35) of a yarn guide conduit (7, 45), further comprising a fluid device for producing a swirl flow around the inlet orifice (6 c, 35) of the yarn guide conduit (7, 45), with the fibre guide surface (28) facing the yarn guide conduit (7, 45), through and by which the fibres (F) can be guided towards the inlet orifice (6 c. 35) of the yarn guide conduit (7, 45), further comprising a guide means (5,
 5. 1, 5.2, 5 c) for at least one continuous thread (C) which is spun over by the fibres (F).
 2. An apparatus as claimed in claim 1 characterized in that the said guide means (5, 5.1, 5.2, 5 c) is contained in the fibre and thread guide means (4).
 3. An apparatus as claimed in claim 1, characterized in that the fibre guide surface (28) of the fibre and thread guide means (4) comprises a fibre delivery edge (29).
 4. An apparatus as claimed in claim 1 or 3, characterized in that the fibre and thread guide means (4) is provided with an arrangement tapering towards the inlet orifice (6 c, 35) of the spindle (6, 32).
 5. An apparatus as claimed in claim 1, characterized in that the fibre and thread guide means (4) comprises a tube-like element (5 c) for guiding at least one continuous thread (C).
 6. An apparatus as claimed in claim 1-5, characterized in that the guide means (5) comprises a groove (5.1) incorporated in the fibre guide surface (28) with the axis of said groove converging substantially into the axis of the yarn guide conduit (7, 45) in true alignment as seen in the direction of the thread run.
 7. An apparatus as claimed in claim 1-5, characterized in that the tube-like element (5 c) is a bore (5.2) extending below the fibre guide surface (28), with the axis of said bore converging substantially into the axis of the yarn guide conduit (7, 45) in true alignment as seen in the direction of the thread run.
 8. An apparatus as claimed in one of the claims 1-7, characterized in that for the purpose of inserting at least one continuous thread (C) apparatus parts on the thread guide means (4) can be moved away from the same.
 9. An apparatus as claimed in claim 8, characterized in that the apparatus parts above or below the tube-like element (5 c) of the thread guide means (4) can be moved away from the same.
 10. An apparatus as claimed in claim 8 or 9, characterized in that the apparatus parts above a groove (5.1) of the thread guide means (4) can be moved away from the same.
 11. An apparatus as claimed in claim 8 or 9, characterized in that the apparatus parts below a bore (5.2) of the thread guide means (4) can be moved away from the same.
 12. A method for producing a spun yarn from a fibre structure which spins over at least one separately supplied continuous thread (C) into a core spun yarn (46), with an apparatus according to claim 1, characterized in that fibres (F) of the fibre structure are guided by means of a fibre guide conduit (13) and a fibre guide surface (28) into an inlet orifice (6 c, 35) of a yarn guide conduit (7, 45) and are spun about at least one continuous thread (C) by a fluid device for producing a swirl flow about the inlet orifice (6 c, 35) of the yarn guide conduit (7, 45), with the at least one continuous thread (C) being guided by a guide means (5) to the inlet orifice (6 c, 35) of the yarn guide conduit (7, 45).
 13. A method for producing a spun yarn from a fibre structure as claimed in claim 12, characterized in that the at least one continuous thread (C) is placed in a fibre and thread guide means (4) for piecing.
 14. A method for producing a spun yarn from a fibre structure as claimed in claim 12, characterized in that the at least one continuous thread (C) is shot into a yarn guide conduit (7, 45) and into a fibre and thread guide means (4) for piecing.
 15. A method for producing a spun yarn from a fibre structure as claimed in claim 12-14, characterized in that the at least one continuous thread (C) is passed at least partly through a fibre and thread guide means (4) for piecing. 